complaints about vibration-induced noise from the ... complaints... · complaints about...

People with solutions

M+P | MBBM group

www.mplusp.eu

Complaints about

vibration-induced noise

from the underground

metro line in Amsterdam

Edwin Nieuwenhuizen

Rail Technology Conferences 2014

Düsseldorf

‒‒

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Amsterdam metro lines


underground metro lines in

historic city centre

OL=‘East Line’

NZ=‘North South Line’

Metro tunnels in Amsterdam (1/2)

‘East Line’

1975 demolition of centre district ‘Nieuwmarkt’

1975-1980 construction of metro tunnel by sinking caisson

method

1980 metro tunnel in service

1980-1985 new residences built on top of tunnel, isolator

pads in building structure to prevent nuisance

2007-2013 complete renovation and replacement of the

rail superstructure

2014 introduction of new rolling stock (M5)


Metro tunnels in Amsterdam (1/2)

‘North South Line’

2009-2012 construction of metro tunnel, partly by drilling

method (TBM)

2017 North South Line in service (anticipated)


Noise and vibration nuisance

recent increase of noise complaints caused by the ‘East Line’

in district Nieuwmarkt

very emotional response by residents

description of nuisance is divergent

in general: increase in noise generated by metro pass-by since

2012

survey goal of M+P (2013): to objectify the complaints and to

find the most probable cause of the increase of number of

complaints

project scope is not yet to find solutions for mitigation


Stakeholders

disturbed residents

several housing corporations

GVB – metro carrier

Dienst Metro – infrastructure manager

other departments of Amsterdam municipality


Project planning

Given: narrow time schedule and limited budget

enumerating possible causes of increased number of

complaints

conducting measurements in June 2013:

▫ simultaneous at tracks, tunnel structure, building foundation

and residential spaces

historic measurement and construction data available in

December 2013

measuring of track roughness in December 2013

final vibration measurements anticipated in April 2014


Tunnel structure example


ground level

building foundation

support beam

caisson deck

caisson wall

concrete column

concrete piles

cross section

2 ballasted tracks

Noise requirements 1980

requirements for residences, imposed by the Department of

Building Inspection of the Amsterdam municipality


day evening night

equivalent Leq 35 dB(A) 30 dB(A) 20 dB(A)

peak LAmax 45 dB(A) 40 dB(A) 30 dB(A)

Mitigation of vibration-induced noise


Amsterdam Pentagon building

no contact between

pavement and facades

rubber isolator pads (609 pcs) between

basement walls and ground floor;

no rigid joints (e.g. piping)

Possible causes of nuisance (1/3)

Receiver (residents)

psycho acoustic effects (negative publicity ‘North South line’)

- sinking buildings along route

- nuisance from construction noise

- construction costs 100% over budget (€1.5 bn)



Transfer path

aging of isolator pads resulting in increase in natural frequency

of mass spring system

occurrence of rigid joints between foundation and ground floor



At the time of renovation of track, acoustic/vibrational

consequences were not considered

Source

new provisions for tunnel safety (airborne noise)

different behavior of new track superstructure (renovation)

longitudinal sagging of the rail bed (renovation)

increase of rail roughness (regular maintenance)

increase of wheel roughness (reduced maintenance of M2/3

stock that will be replaced by M5)

new train configuration (3 coupled carriages)


Measurements in residential space (1/2)

Amsterdam Pentagon building, 3th floor – June 2013

LAmax is higher than 30 dB(A) limit

80 Hz 1/3 octave band is predominant and responsible for

nuisance

pass-by on southbound track noisier than vice versa (+8 dB)

metros with 3 carriages noisier than with 2 (+2 dB)

wall vibration level matches noise level: no airborne transfer

path


Measurements in residential space (2/2)


30

40

50

60

70

25 31,5 40 50 63 80 100 125

Lp,m

ax [

dB

]

f [Hz] 1/3 oct

30 dB(A)

southbound; 3 carriages


northbound; 3 carriages


Measurements in basement (1/3)

Amsterdam Pentagon building, basement – June 2014

quick inspection revealed possible deviations:

- not all isolator pads are load bearing

- flexible joints between non-bearing walls and ground

floor are not visible (rigid contacts?)

- no gap between pavement and facade

in situ measured insertion loss of rubber pads is about 15 dB

at 80 Hz

vibration levels on ground floor highest above supposed non-

bearing walls and near facades (reveals a vibration bypass)




-5

5

15

25

35

25 32 40 50 63 80 100

insert

ion

loss ∆

LV [

dB

]

f [Hz] 1/3 oct

isolator pad #1

isolator pad #2

isolator pad #3

in theory (fn =14 Hz)



bearing

wall

non-bearing

wall

facade

building foundation

ground floor

pavement

80 Hz 1/3 oct vibration level, relative to tunnel deck

∆Lv =

-24 dB

∆Lv =

-9 dB ∆Lv =

-11 dB

isolator pads

Measurements on tunnel wall

Date

Caisson

nr

South-

bound

North-

bound

21-7-1980 02.08 60 56

1-3-1983 02.08 68 60

24-8-1985 52.05 68 63

24-8-1985 52.07 64 65

27-6-2013 km 1.100 66 58


apparently no significant

increase in vibration level

since the 80’s

but source-related causes

may not be rejected yet:

- not exact same

measurement position

- large scatter (±4 dB)

- relatively limited number

of pass-bys

Lv [dB re 50 10-8 ms-1]

western tunnel wall, curved track

horizontal direction

Measurement on rail foot (1/3)

metros with 3 carriages cause higher vibration levels than with

2 carriages

average vibration level of southbound track is higher than

northbound

metros change direction at CS: wheel roughness is probably

not the cause

vertical Track Decay Rates of tracks seem normal




105

115

125

135

145

25 32 40 50 63 80 100 125

LV

E [

dB

re 1

0-9

m/s

]

f [Hz]





average of inner and outer rail



0

1

10

25 31,5 40 50 63 80 100 125

Tra

ck D

eca

y R

ate

[d

B/m

]

f [Hz] 1/3 oct

outer rail of southbound track

inner rail of southbound track

outer rail of northbound track

inner rail of northbound track

Rail roughness measurements (1/2)

Measurements done prior to rail head grinding

80 Hz at 60 km/h, thus λ=20 cm

no peak at 20 cm that explains noise at 80 Hz

no decrease in complaints after rail head grinding (Jan 2014)

rail roughness is probably not the cause of nuisance


Rail roughness measurements (2/2)


-20

-15

-10

-5

0

5

10

15

31,5

0

25,0

0

20,0

0

16,0

0

12,5

0

10,0

0

8,0

0

6,3

0

5,0

0

4,0

0

3,1

5

2,5

0

2,0

0

1,6

0

1,2

0

1,0

0

0,8

0

0,6

3

0,5

0

0,4

0

0,3

2

Lr [d

B r

e.

1 μ

m]

wave length [cm]

reference track

outer rail of southbound track

inner rail of southbound track

λ=20 cm

Conclusions

metro pass-by noise level in residence is higher than

requirements of 1980

bypass of vibration isolators pads most probable cause of

nuisance, possibly caused by resettling of building and/or

street repaving

it is unlikely that the cause is source-related, but this needs to

verified by final measurements, anticipated in April 2014


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